FSQ is a Fast Simple QSO mode designed specifically for HF. It works well under NVIS and sunrise/sunset conditions on the lower bands, and also works well for short skip on higher bands. It can also be used on VHF FM, and clearly has a much wider useful range of operating conditions that other more conventional digital modes. FSQ transmission is also well within the capability of micro-controller based devices for low-power propagation transmissions (MEPT). The FSQ modulation, coding and FSQCALL protocol are publicly disclosed and described, and the software is open source.